Symptomatic Upper Extremity Deep Venous Thrombosis After Laser Lead Extraction

Introduction Laser lead extraction is a well-established method for removing unwanted leads with low morbidity and mortality. In this small series of cases, we documented our experience with venous thrombosis after laser lead extraction. Methods Retrospective data of patients who underwent laser lead extraction with postoperative axillo-subclavian vein thrombosis between May 2010 and January 2020 were analyzed. Demographic, operative, clinical, and follow-up characteristics of those patients were collected from our medical database. Results Six patients underwent percutaneous laser lead extraction. Mean age of the patients was 64±7 years. And four of them were male. A total of 11 leads with a mean age of 92±43.8 months were extracted. Patients presented with painful arm swelling postoperatively. Conclusion Laser lead extraction may lead to symptomatic upper extremity deep venous occlusion.


INTRODUCTION
The implantation of cardiac implantable electronic devices (CIED) is a common procedure due to increasing indications for its use to improve survival and the quality of life in patients with cardiac rhythm disorders [1,2] . Proportional to this increase there is also an increase in the complications related to those devices, like infections and dysfunction, which makes its removal a necessity [3][4][5][6] . Many techniques were developed for lead extraction but most of them were ineffective especially in removing very old leads [3,4,7] . The introduction of laser lead extraction gave the doctors a good tool for lead extraction, which has a high success rate and a relatively low risk profile [8][9][10][11] . However, this low risk profile includes some serious complications that may alter the whole prognosis of a patient after laser lead extraction. Axillo-subclavian vein thrombosis is a rare illness. To the best of our knowledge, its association with laser lead extraction was not reported until now in the literature. The aim of this study is to turn the light on some of the cases in our cohort who had suffered from symptomatic deep vein thrombosis after laser lead extraction.

METHODS
All patients who underwent laser lead extraction at Heidelberg University Hospital (Heidelberg, Germany), from May 2010 to July 2021, were retrospectively investigated. We screened the records to identify patients who suffered from axillo-subclavian thrombosis as postoperative complication of laser lead extraction. We gathered demographic, preoperative, intraoperative, and postoperative data of the affected subjects. The diagnosis of axillosubclavian vein thrombosis was based on clinical symptoms, physical examination, and imaging tests. Patients were referred from external hospitals or from our electrophysiological outpatient clinic. Indications for lead extraction were pocket infection, device-related endocarditis, pain, and abandoned or non-functioning leads at the time. Pocket infection was defined as redness with or without purulent discharge from the device pocket or device erosion which may be accompanied by pain. Device-related endocarditis was defined as persistent bacteremia or sepsis in the absence of another identifiable source or the presence of vegetations on the leads or valves. Pain related to CIED or leads was considered also as an indication for extraction. Extraction of abandoned or non-functioning leads is performed if they produce obstruction to a venous system or if a new lead implantation will increase the burden of the total lead number. The use of laser sheath was indicated if the removal of the leads under simple traction was not successful. All procedures were performed under general anesthesia with continuous arterial blood pressure monitoring. Under fluoroscopic guidance, the lead extraction starts by inserting a lead locking stylet into the inner coil lumen, then a suture is tied around the insulation and the locking stylet. After that, the laser sheath (GlideLight™ 80 Hz, 14 or 16 French) was advanced over the lead until the locking stylet emerged from the other side of the laser sheath. Laser was then applied while gradually advancing the sheath over the lead under traction until the lead was freed. Transesophageal echocardiography was used to monitor the procedure. In patients with local or systemic infection, no device would be implanted unless the patient is pacemaker dependent.
In that case, an epicardial pacemaker lead is implanted through an inferior pericardiotomy [12] , and after remission of infection, the patient would be re-evaluated for dual-chamber pacemaker implantation.
For statistical analysis, continuous variables are expressed as mean or median and categorical variables are reported as frequency and percentages. Continuous variables were compared using a twosample t-test.
The study proposal was approved by the Heidelberg University ethics commission (S-597/2019). All patients in this study consented to use of their medical records for research purposes.

RESULTS
During the 11 years of study period, we performed percutaneous laser lead extractions in 274 patients, of which six patients (1.82%) suffered from axillo-subclavian vein thrombosis. Patient characteristics can be seen in Table 1.
Mean age of the patients was 64±7 years. A total of 11 leads with a mean age of 92±43.8 months were extracted. All leads were completely extracted except in patient No. 1, in whom the double-coil lead was partially removed. Types of extracted leads are listed in Table 2.
All patients presented with arm swelling and purplish discoloration.

DISCUSSION
The pathogenesis of axillo-subclavian vein thrombosis after percutaneous laser lead extraction is not well understood. The long-lying leads develop adhesions and fibrosis in the venous system making simple removal troublesome. This fibrosis depends on the dwell time of the hardware and young patient age [12] . The use of laser sheaths bears the risk of inducing vessel or organ injury    and sometimes embolism of tissue fragments [8,11] . As described by Tarakji et al. [13] , the removed leads contain remnants of vascular, atrial, and ventricular tissue, which creates abrasive surfaces in the venous system. The exposure of those surfaces to blood flow may trigger thrombus formation and vein occlusion. Albertini et al. [14] has also detected a significant degree of upper extremity deep venous thrombosis occurring after laser lead extraction, which is often underdiagnosed. In addition, the remnant of partially removed leads, as in patient No.1, may also enhance this thrombotic effect. Also, the number of the extracted leads plays a role in this process as an increase in the number of laser rounds may increase the abraded surface area in the vein making thrombus formation more likely. The use of balloon angioplasty may alleviate the symptoms and gives time for the development of collateral circulation, but central vein patency may not be long-lasting. Generally, unilateral axillo-subclavian thrombosis can be well tolerated, and the symptoms subside over time under the use of anticoagulants with compression bandages and arm elevation, as collateral circulation develops to reduce the congestion. The only permanent problem is that the affected veins in our case series are not available for future lead implantation. Also, axillo-subclavian thrombosis may not cause complete venous occlusion, and in this way, it will be clinically symptomatic. This asymptomatic partial or complete occlusion of the axillo-subclavian vein will make future lead implantation questionable. Fu et al. [15] reported three patients with superior vena cava syndrome after laser lead extraction with subsequent lead implantation. Also, Ghosh et al. [16] reported three cases of venous thrombosis after laser lead extraction. This may raise the question, whether the venous thrombosis was a result of the extraction or the implantation [17] or both. Also, the use of laser lead extraction in a stenosed vein, as in patient No. 3, may increase the chances of postoperative venous thrombosis as the generated tunnel is composed of injured surfaces, which are more amenable to thrombosis.

Limitations
This study included a limited number of patients. A bigger multicentric study should give more information about such complications and the possible methods to manage them.

CONCLUSION
Laser lead extraction may cause symptomatic venous occlusion affecting patients' quality of life. A larger number of patients with a longer follow-up duration and frequent postoperative testing are needed to identify the patients at risk and to uncover silent venous thrombosis. Intravenous heparin followed by oral anticoagulants and venoplasty of the superior vena cava occlusion should help alleviating the symptoms. Discovering silent thrombosis may alter our approach to laser lead extraction.